Activation of Lysozyme and Lactoferrin in Endolymphatic Duct of Rats / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Secretory activity, particularly of antibacterial agents such as lysozyme and lactoferrin, is an important aspect of the mucosal defense mechanism. The development of these agents may have a direct bearing on the susceptibility of the mucosa to infection. The antibacterial secretory enzymes such as lysozymes and lactoferrins are found in various mucosal tissues, and it has been suggested that these enzymes contribut to the defense against local mucosal infection. Specifically, lysozyme and lactoferrin are important components of innate immunity against pathogens at mucosal surfaces. The purpose of this study is to identify the distribution and expression of lysozyme, lactoferrin in endolymphatic duct of rat. MATERIALS AND METHOD: Normal rats (129P3/J, 10 cases) were used for this study. The expression level and distribution of lysozyme mRNA were analyzed by RT-PCR and quantitative image analysis. RESULTS: The expression of lysozyme and lactoferrin mRNA in endolymphatic ducts of rats was compared by quantitative image analysis. The results indicate that the relative expression of lysozyme mRNA resulted as 2.5 times greater than that of lactoferrin mRNA. CONCLUSION: The distribution and expression of lysozyme and lactoferrin in the endolymphatic duct of rat were identified. The study suggests that innate immunity such as lysozyme and lactoferrin are important components of defense mechanisms along with mucociliary clearance. Additionally, the authors think that the activity of lysozymes is more effective than that of lactoferrin in the endolymphatic duct of rat.

Relationship of the Area Measurement of the Large Endolymphatic Duct and Sac Syndrome as well as the Clinical Symptoms with CT and MR Imaging Results

PURPOSE: To evaluate the CT and MRI findings of the large endolymphatic duct or sac syndrome (LEDS) and its associated anomalies, with clinical features. MATERIALS AND METHODS: We retrospectively reviewed the MR and CT images of 52 ears obtained from 26 patients with LEDS. We reviewed the clinical findings, audiology testing, and treatment results. The degree of hearing loss was classified from normal to profound, based on pure tone audiometry. The largest areas were measured at each endolymphatic duct and analyzed to determine whether a correlation exists with the degree of hearing loss. We also analyzed the differences in measurements between CT and MRI findings. RESULTS: All 26 patients had some degree of sensorineural hearing loss, which resulted in 18 ears to undergo a cochlear implantation. One patient was diagnosed with Cornelia de Lange syndrome. Five patients had a sudden hearing loss onset. Ten ears had incomplete cochlear partitions, whereas 28 ears had enlarged vestibules. All patients had severe to profound hearing loss. We found no statistical correlation between the size of the largest area of the endolymphatic duct and the degree of hearing loss. The mean area of the endolymphatic ducts, as per an MRI examination, revealed slightly greater areas than the CT findings, although the differences were not significant. CONCLUSION: Enlarged vestibules and incomplete partitions of the cochlea were common anomalies associated with LEDS. We found no statistical correlation between the largest area of the endolymphatic duct or sac with the degree of hearing loss.

Initiation of Endolymphatic Hydrops after Resection of the Endolymphatic Duct / 대한이비인후과학회지

While data from animal models have shown endolymphatic hydrops to be developed following the obstruction of the endolymphatic duct, such connection has not yet been established in humans. This study reports on a case of hearing loss at low frequencies, tinnitus and aural fullness after removal of a clival oculomotor schwannoma via retrolabyrinthine approach that included resection of the endolymphatic duct. Commencement of a low salt diet and diuretic medication resulted in almost complete recovery of hearing, although some subtle tinnitus and aural fullness persisted. The clinical outcome supports the appearance of this case to be an evidence of initiation of endolymphatic hydrops due to resection of the endolymphatic duct.